The present invention generally relates to laundry detergents. More particularly, the invention relates to the use of surfactant mixtures which provide enhanced cleaning performance at lower actives levels.
A wide variety of detersive surfactants are known in the literature and in commercial practice. Such surfactants range from common soap to sophisticated betaine and sulfobetaine synthetic surfactants. In general, the continuing search for improved detersive surfactants has been the result of the desires of the formulator to meet a growing list of cleaning needs under a wide variety of conditions. Thus, the formulator of laundry detergents must provide products which remove from fabrics a wide variety of soils and stains, ranging from petroleum oils and fatty oils to proteins, carbohydrates, clay and other particulate soils and mixtures of such soils and stains.
The most widely used surfactants in detergent compositions are nonionics, anionics, amphoterics, zwitterionics and, to some extent, cationics. It is often times desirable to employ mixtures of these types of surfactants in order to both enhance their performance and reduce the cost associated with their formulation, since certain surfactants are more costly than others.
Moreover, with the advent of increased ecotoxicological awareness, it is becoming more desirable to formulate compositions which are more environmentally friendly. This goal can be both achieved, and furthered, if it were possible to formulate detergent compositions which not only employed surfactants obtainable from renewable natural resources, but also, if detergents could be formulated using smaller amounts of ingredients (actives) without a concomitant loss in cleaning effectiveness.
The present invention is directed to the surprising discovery that by combining surfactants having matching carbon chain length distributions in their hydrophobic groups, enhanced cleaning performance can be obtained at lower surfactant concentration levels.
Thus, the present invention is directed to a surfactant composition containing a mixture of at least two surfactants selected from the group consisting of nonionics, anionics, cationics, amphoterics, and mixtures thereof, wherein the surfactants have matching hydrophobic groups.
The present invention is also directed to a process for making an improved surfactant composition involving combining at least two surfactants selected from the group consisting of nonionics, anionics, cationics, amphoterics, zwitterionics and mixtures thereof, with the proviso that the surfactants have matching hydrophobic groups.
The present invention is also directed to a cleaning formulation containing from about 5 to about 50% by weight, based on the weight of the formulation, of the above-disclosed surfactant mixture.